My primary use of the numeric keypad is to control window positioning on Windows using a utility called WinSplit Revolution. It uses a Ctrl+Alt prefix before each numpad number to auto-position windows in the various quadrants of the screen that correspond to the physical numpad layout. The shortcuts only work with Ctrl+Alt+Numpad4 (for example), not Ctrl+Alt+4. I assume other apps take a similar dependency on numpad-only numbers, but maybe not. If this turns out to be limited just to my particular scenario then no big deal, I'll just remap the shortcuts for WinSplit Revolution.